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MODIFIED BERNOULLI ITERATION METHODS FOR QUADRATIC MATRIX EQUATION

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Journal of Computational Mathematics 2007年第5期25卷 498-511页

作者： zhong-zhi Bai yong-Hua Gao LSEC ICMSEC Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China

We construct a modified Bernoulli iteration method for solving the quadratic matrix equation AX^2 ＋ BX ＋ C = 0, where A, B and C are square matrices. This method is motivated from the Gauss-Seidel iteration for solving linear systems and the ShermanMorrison-Woodbury formula for updating matrices. Under suitable conditions, we prove the local linear convergence of the new method. An algorithm is presented to find the solution of the quadratic matrix equation and some numerical results are given to show the feasibility and the effectiveness of the algorithm. In addition, we also describe and analyze the block version of the modified Bernoulli iteration method.

关键词： Quadratic matrix equation Quadratic eigenvalue problem Solvent Bernoulli's iteration Newton's method Local convergence.

A concise synthesis of (±)-pregabalin via intramolecular C-H insertion of N-cumyl á-diazoacetamide

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合成化学 2004年第z1期12卷 31-31页

作者： CHEN Zhen-liang LIU Wei-jun CHEN zhi-yong Jiang Yao-zhong HU Wen-hao Key laboratory for Asymmetric Synthesis and Chiratechnology Chengdu Institute of Organic Chemistry Chinese Academy of Sciences Chengdu 610041 China Key laboratory for Asymmetric Synthesis and Chiratechnology Chengdu Institute of Organic Chemistry Chinese Academy of Sciences Chengdu 610041 China Key laboratory for Asymmetric Synthesis and Chiratechnology Chengdu Institute of Organic Chemistry Chinese Academy of Sciences Chengdu 610041 China Key laboratory for Asymmetric Synthesis and Chiratechnology Chengdu Institute of Organic Chemistry Chinese Academy of Sciences Chengdu 610041 China Key laboratory for Asymmetric Synthesis and Chiratechnology Chengdu Institute of Organic Chemistry Chinese Academy of Sciences Chengdu 610041 China

Pregabalin 1 (3-aminomethyl-5-methyl hexanoic acid) is a potent anticonvulsant related to the inhibitory neurotransmitter a-aminobutyric acid (GABA).1 In preclinical trials of anticonvulsant activity, pregabalin is three to ten times more potent than gabapentin. Therefore,pregabalin can be used for the potential treatment of several central nervous system (CNS) disorders including epilepsy, neuropathic pain, anxiety and social phobia. Many synthetic routes have been developed to prepare pregabalin.2-3 However, there is a need to explore novel, practical and better synthetic approaches to pregabalin. Herein we report a concise synthesis of (±)-pregabalin from hydrolysis of corresponding (a)-lactam, which was obtained from the intramolecular C-H insertion of N-cumyl a-diazoacetamide 4.

关键词： Pregabalin, C-H insertion,(a)-lactam

Dose reconstruction with Compton camera during proton therapy via subset-driven origin ensemble and double evolutionary algorithm

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Nuclear Science and Techniques 2023年第4期34卷 135-148页

作者： zhi-Yang Yao yong-Shun Xiao Ji-zhong Zhao Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle&Radiation Imaging(Tsinghua University) Ministry of EducationBeijing 100084China

Compton camera-based prompt gamma(PG) imaging has been proposed for range verification during proton therapy. However, a deviation between the PG and dose distributions, as well as the difference between the reconstructed PG and exact values, limit the effectiveness of the approach in accurate range monitoring during clinical applications. The aim of the study was to realize a PG-based dose reconstruction with a Compton camera, thereby further improving the prediction accuracy of in vivo range verification and providing a novel method for beam monitoring during proton therapy. In this paper, we present an approach based on a subset-driven origin ensemble with resolution recovery and a double evolutionary algorithm to reconstruct the dose depth profile(DDP) from the gamma events obtained by a cadmium-zinc-telluride Compton camera with limited position and energy resolution. Simulations of proton pencil beams with clinical particle rate irradiating phantoms made of different materials and the CT-based thoracic phantom were used to evaluate the feasibility of the proposed method. The results show that for the monoenergetic proton pencil beam irradiating homogeneous-material box phantom,the accuracy of the reconstructed DDP was within 0.3 mm for range prediction and within 5.2% for dose prediction. In particular, for 1.6-Gy irradiation in the therapy simulation of thoracic tumors, the range deviation of the reconstructed spreadout Bragg peak was within 0.8 mm, and the relative dose deviation in the peak area was less than 7% compared to the exact values. The results demonstrate the potential and feasibility of the proposed method in future Compton-based accurate dose reconstruction and range verification during proton therapy.

关键词： Prompt gamma imaging Dose reconstruction Range verification Origin ensemble Compton camera Evolutionary algorithm

PREPARATION OF POLY(METHYL METHACRYLATE)/LAYERED DOUBLE HYDROXIDES NANOCOMPOSITES via in situ SOLUTION POLYMERIZATION

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Chinese Journal of Polymer Science 2007年第6期25卷 573-579页

作者： Ang-ran Wang yong-zhong Bao zhi-xue Weng zhi-ming Huang State Key Laboratory of Chemical Engineering Zhejiang University Hangzhou 310027 China

An exfoliated layered double hydroxides/poly（methyl methacrylate）（LDHs/PMMA） nanocomposite was prepared by in situ solution polymerization of methyl methacrylate （MMA） in the presence of 4-vinylbenzenesulfonate intercalated LDHs（MgAl-VBS LDHs）. MgAl-VBS LDHs was prepared by the ion exchange method, and the structure and composition of the MgAl-VBS LDHs were determined by X-ray diffraction （XRD）, infrared spectroscopy and elemental analysis. XRD and transmission electron microscopy （TEM） were employed to examine the structure of LDHs/PMMA nanocomposite. It was indicated that the LDHs layers were well exfoliated and dispersed in the PMMA matrix. The grafting of PMMA onto LDHs was confirmed by the extraction result and the weight fraction of grafted PMMA increased as the weight fraction of LDHs in the nanocomposites increased.

关键词： Nanocomposite Poly(methyl methacrylate) Layered double hydroxides.

Interface microstructure evolution and bonding strength of TC11/c-TiA l bi-materials fabricated by laser powder deposition

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Rare Metals 2016年第6期35卷 456-462页

作者： zhi-Jun Xu yong-zhong Zhang Ming-Kun Liu Xin-yong Gong Center for Composites General Research Institute for Nonferrous Metals Beijing 100088 China

Laser powder deposition was applied to fabricate the Ti-6.5Al-3.5Mo-1.5Zr-0.3Si （wt%）/Ti-47Al- 2Cr-2Nb-0.2W-0.15B （at%） bi-material system. The asdeposited TC11 alloy shows a basket-wave-like morphology while the as-deposited y-TiAl alloy consists of fully α2/γ lamellar microstructures. Regarding the thermal mismatch between TC11 and γ-TiAl during processing, the interface microstmcture evolution was concerned. The transformation pathway was illustrated. It is found that the content changes of Al elements and β-stabilizers Mo, Cr, and Nb are responsible for the evolution of microstructures at the interface. The fracture surfaces are located at the y-TiAl side. The bi-material shows a brittle-fracture manner, with the ultimate tensile strength of 560 MPa.

关键词： Laser powder deposition TC11 titanium alloy γ-TiAl alloy Bi-material Interface

Electrical properties of a generalized 2×n resistor network

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Communications in Theoretical Physics 2023年第7期75卷 145-154页

作者： Shi Zhou zhi-Xuan Wang yong-Qi Zhao zhi-zhong Tan Department of physics Nantong UniversityNantong 226019China

Any changes in resistor conditions will increase the difficulty of resistor network *** paper considers a new model of a generalized 2×n resistor network with an arbitrary intermediate axis that was previously *** investigate the potential function and equivalent resistance of the 2×n resistor network using the RT-I *** RT-I method involves four main steps:(1)establishing difference equations on branch currents,(2)applying a matrix transform to study the general solution of the differential equation,(3)obtaining a current analysis of each branch according to the boundary constraints,and(4)deriving the potential function of any node of the 2×n resistor network by matrix transformation,and the equivalent resistance formula between any *** article concludes with a discussion of a series of special results,comparing and verifying the correctness of the *** work establishes a theoretical basis for related scientific research and application.

关键词： generalized network difference equations matrix transform potential function equivalent resistance

Risk factors of development of gut-derived bacterial translocation in thermally injured rats

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World Journal of Gastroenterology 2004年第11期10卷 1619-1624页

作者： zhong-TangWang yong-MingYao Guang-XiaXiao zhi-yongSheng DepartmentofMicrobiologyandImmunology BurnsInstitute304thhospitalofPLABeijing100037China InstituteofBurnResearch SouthwesternHospitalThirdMilitaryMedicalUniversityChongqing400038China

AIM: Studies have demonstrated that gut-derived bacterial translocation (BT) might play a role in the occurrence of sepsis and multiple organ dysfunction syndrome (MODS). Yet, no convincing overall analysis of risk factors for BT has been reported. The purpose of this study was to evaluate the related factors for the development of BT in burned rats. METHODS: Wistar rats were subjected to 30% third-degree burns. Then samples were taken on postburn d 1, 3, and 5. Incidence of BT and counts of mucosal bifidobacteria, fungi and *** mucus sIgA, degree of injury to ileal mucosa, and plasma interleukin-6 were observed. Univariate analysis and multivariate logistic regression analysis were performed. RESULTS: The overall BT rate was 53.9% (69 in 128). The result of univariate analysis showed that the levels of plasma endotoxin and interleukin-6, the counts of mucosal fungi and E. coli and the scores of ileum lesion were markedly increased in animals with BT compared with those without (P=0.000-0.005), while the levels of mucus sIgA and the counts of mucosal bifidobacteria were significantly reduced in animals with translocation compared with those without (P=0.000). There was a significant positive correlation between mucus sIgA and the counts of mucosal bifidobacteda (r=0.74, P=0.001). Moreover, there were strong negative correlations between scores of ileum-lesion and counts of bifidobacteria (r=-0.67, P=-0.001). Multivariate logistic regression revealed that ileum lesion score (odds ratio [OR] 45.52, 95% confidence interval [CI] 5.25-394.80), and counts of mucosal bifidobacteria (OR 0.039, 95% CI 0.0032-0.48) were independent predictors of BT secondary to severe burns. CONCLUSION: Ileal lesion score and counts of mucosal bifidobacteria can be chosen as independent prognosis factors of the development of BT. Specific interventions targeting these high-risk factors might be implemented to attenuate BT, including strategies for repair of damaged intestinal mucosae and r

关键词：内脏细菌细菌感染热损伤老鼠 MODS 多脏器功能衰竭综合症

Quartz luminescence dating of a centennial coastal foredune from Changle in Fujian Province,East China Sea

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Journal of Mountain Science 2022年第9期19卷 2601-2610页

作者： JIN Jian-hui LI zhi-zhong LING zhi-yong QIU Jun-jie Key Laboratory for Subtropical Resources and Environment of Fujian Province Fujian Normal UniversityFuzhou 350007China School of Geographical Sciences Fujian Normal UniversityFuzhou 350007China Qinghai Institute of Salt Lakes Chinese Academy of SciencesXi'ning 810008China

The Aeolian foredunes in the southern coast of China are records of paleoenvironmental changes for marine monsoon region. Intensive studies have been conducted to decipher their formation and paleoenvironmental implications in which chronology played a key role. However, robust dating results are still limited due to the scarcity of organic materials for radiocarbon and the limited application of quartz optically stimulated luminescence(OSL). Here, we collected 11 OSL samples and 140 grainsize samples from the Changle section with a thickness of 7 m from a coastal foredune in Fujian Province. The dating results indicated that the section spanned a time period from 0.32±0.04 ka(depth of 700 cm) to 0.18±0.02 ka(depth of 80 cm), after removal of age outliers. According to the OSL ages and sedimentary structural characteristics, the section could be divided into two stages, i.e. the stable accumulation period with an age range of 0.32-0.18 ka from the depth of 700 cm to 80 cm, and the activation period above the depth of 60 cm, at which the dune erosion was retained. The foredune development due to increased transport of dune sediment at the top part of the section was the result of recent human *** the foredunes, normal cross-bedding was generated by seasonal changes in wind *** changes in the wind direction were the primary cause for various sedimentary bedding within the dunes.

关键词： Optically stimulated luminescence Grain size Oblique foredune Coastal South China

Trajectory optimization of a deflectable nose missile

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Defence Technology（防务技术） 2017年第3期13卷 158-163页

作者： zhi-yong Zhang Qi-zhong Tang Xiao-hui Sun zhi-hua Chen National Key Laboratory of Transient Physics Nanjing University of Science and Technology North China System Engineering Institute

The deflectable nose missile has a longer range by deflecting its nose to improve its aerodynamic *** on detached eddy simulation(DES), the supersonic flow fields of a missile with deflectable nose are simulated numerically and its aerodynamic force coefficients are calculated under the condition of the deflection angles vary from 0° to 8°, angles of attack, 0°-8°, and mach numbers, 2 to 5. Coupling these aerodynamic coefficients with the plumb plane ballistic equations, the extended flight range has been calculated. Furthermore, the genetic algorithm(GA) is employed for the solution of maximum range of the deflected missile.

关键词：偏转角度导弹弹道优化弹头流场数值模拟最大射程动力学特征气动力系数